Retractable keyboard keys

ABSTRACT

A keyboard includes a bezel having a plurality of key openings and a plurality of key holding features configured adjacent to the plurality of key openings on a bottom side of the bezel. A plurality of keycaps are positioned within the plurality of key openings. A chassis is included that has a plurality of planar-translation effecting mechanisms each supporting a respective one of the plurality of keycaps to guide the respective keycap in a press direction and a second direction as the keycap moves from the unpressed position toward the pressed position. The keypad or keyboard includes a key retraction mechanism configured to move the chassis relative to the bezel wherein the key holding features of the bezel limit movement of the keycaps in the second direction during movement of the chassis relative to the bezel, while the planar-translation effecting mechanisms move the plurality of keycaps toward a retracted position.

RELATED APPLICATION(S)

This application claims priority to Provisional Patent Application No.61/839,048 filed Jun. 25, 2013 and to Provisional Patent Application No.61/814,013 filed Apr. 19, 2013.

FIELD OF THE INVENTION

This invention generally relates to electronic devices.

BACKGROUND OF THE INVENTION

Pressable touchsurfaces (touch surfaces which can be pressed) are widelyused in a variety of input devices, including as the surfaces of keys orbuttons for keypads or keyboards, and as the surfaces of touch pads ortouch screens. It is desirable to improve the usability of these inputsystems.

FIG. 2 shows a graph 200 of an example tactile response curve associatedwith the “snapover” haptic response found in many keys enabled withmetal snap domes or rubber domes. Specifically, graph 200 relates forceapplied to the user by a touchsurface of the key and the amount of keydisplacement (movement relative to its unpressed position). The forceapplied to the user may be a total force or the portion of the totalforce along a particular direction such as the positive or negativepress direction. Similarly, the amount of key displacement may be atotal amount of key travel or the portion along a particular directionsuch as the positive or negative press direction.

The force curve 210 shows four key press states 212, 214, 216, 218symbolized with depictions of four rubber domes at varying amounts ofkey displacement. The key is in the “unpressed” state 212 when no pressforce is applied to the key and the key is in the unpressed position(i.e., “ready” position). In response to press input, the key initiallyresponds with some key displacement and increasing reaction forceapplied to the user. The reaction force increases with the amount of keydisplacement until it reaches a local maximum “peak force” F₁ in the“peak” state 214. In the peak state 214, the metal snap dome is about tosnap or the rubber dome is about to collapse. The key is in the“contact” state 216 when the keycap, snap dome or rubber dome, or otherkey component moved with the keycap makes initial physical contact withthe base of the key (or a component attached to the base) with the localminimum “contact force” F₂. The key is in the “bottom” state 218 whenthe key has travelled past the “contact” state and is mechanicallybottoming out, such as by compressing the rubber dome in keys enabled byrubber domes.

A snapover response is defined by the shape of the reaction forcecurve—affected by variables such as the rate of change, where it peaksand troughs, and the associated magnitudes. The difference between thepeak force F₁ and the contact force F₂ can be termed the “snap.” The“snap ratio” can be determined as (F₁−F₂)/F₁ (or as 100*(F₁−F₂)/F₁, if apercent-type measure is desired).

BRIEF SUMMARY OF THE INVENTION

Retractable key assemblies for keypads and keyboards are disclosed. Akeypad or keyboard includes a bezel having a plurality of key openingsand a plurality of key holding features configured adjacent to theplurality of key openings on a bottom side of the bezel. A plurality ofkeycaps are positioned within the plurality of key openings. Each keycaphas a touch surface for receiving a press force that moves the keycapfrom an unpressed position toward a pressed position, the unpressedposition and pressed position being separated in a press direction and asecond direction orthogonal to the press direction. A chassis isincluded that has a plurality of planar-translation effecting mechanismseach supporting a respective one of the plurality of keycaps to guidethe respective keycap in the press direction and the second direction asthe keycap moves from the unpressed position toward the pressedposition. The keypad or keyboard includes a key retraction mechanismconfigured to move the chassis relative to the bezel wherein the keyholding features of the bezel limit movement of the keycaps in thesecond direction during movement of the chassis relative to the bezel,while the planar-translation effecting mechanisms move the plurality ofkeycaps toward a retracted position.

BRIEF DESCRIPTION OF DRAWINGS

Example embodiments of the present invention will hereinafter bedescribed in conjunction with the appended drawings which are not toscale unless otherwise noted, where like designations denote likeelements, and:

FIG. 1 shows an example keyboard that incorporates one or moreimplementations of key-based touchsurfaces configured in accordance withthe techniques described herein;

FIG. 2 is a graph of an example tactile response that is characteristicof many keys enabled with metal snap domes or rubber domes;

FIGS. 3 A-B are simplified side views of a first example touchsurfaceassembly configured in accordance with the techniques described herein;

FIG. 4 shows an exploded view of an example keyboard in accordance withthe techniques described herein

FIGS. 5 A-B are cross-sectional side views of a key assembly inaccordance with an embodiment;

FIGS. 6 A-C are side views of an exemplary laptop computer in accordancewith an embodiment;

FIGS. 7 A-D are perspective views of an exemplary key retractionmechanisms in accordance with an embodiment;

FIGS. 8 A-B are side views of an exemplary four-bar key retractionmechanism in accordance with an embodiment; and

FIGS. 9 A-B are side views of an exemplary four-bar key retractionmechanism in accordance with an embodiment.

DETAILED DESCRIPTION OF THE INVENTION

The following detailed description is merely exemplary in nature and isnot intended to limit the invention or the application and uses of theinvention.

Various embodiments of the present invention provide input devices andmethods that facilitate improved usability, thinner devices, easierassembly, lower cost, more flexible industrial design, or a combinationthereof. These input devices and methods involve pressable touchsurfacesthat may be incorporated in any number of devices. As some examples,pressable touchsurfaces may be implemented as surfaces of touchpads,touchscreens, keys, buttons, and the surfaces of any other appropriateinput device. Thus, some non-limiting examples of devices that mayincorporate pressable touchsurfaces include personal computers of allsizes and shapes, such as desktop computers, laptop computers, netbooks,ultrabooks, tablets, e-book readers, personal digital assistants (PDAs),and cellular phones including smart phones. Additional example devicesinclude data input devices (including remote controls, integratedkeyboards or keypads such as those within portable computers, orperipheral keyboards or keypads such as those found in tablet covers orstand-alone keyboards, control panels, and computer mice), and dataoutput devices (including display screens and printers). Other examplesinclude remote terminals, kiosks, point-of-sale devices, video gamemachines (e.g., video game consoles, portable gaming devices, and thelike) and media devices (including recorders, editors, and players suchas televisions, set-top boxes, music players, digital photo frames, anddigital cameras).

The discussion herein focuses largely on rectangular touchsurfaces.However, the touchsurfaces for many embodiments can comprise othershapes. Example shapes include triangles, quadrilaterals, pentagons,polygons with other numbers of sides, shapes similar to polygons withrounded corners or nonlinear sides, shapes with curves, elongated orcircular ellipses circles, combinations shapes with portions of any ofthe above shapes, non-planar shapes with concave or convex features, andany other appropriate shape.

In addition, although the discussion herein focuses largely on thetouchsurfaces as being atop rigid bodies that undergo rigid body motion,some embodiments may comprise touchsurfaces atop pliant bodies thatdeform. “Rigid body motion” is used herein to indicate motion dominatedby translation or rotation of the entire body, where the deformation ofthe body is negligible. Thus, the change in distance between any twogiven points of the touchsurface is much smaller than an associatedamount of translation or rotation of the body.

Also, in various implementations, pressable touchsurfaces may compriseopaque portions that block light passage, translucent or transparentportions that allow light passage, or both.

FIG. 1 shows an example keyboard 100 that incorporates a plurality of(two or more) pressable key-based touchsurfaces configured in accordancewith the techniques described herein. The example keyboard 100 comprisesrows of keys 120 of varying sizes surrounded by a keyboard bezel 130.Keyboard 100 has a QWERTY layout, even though the keys 120 are not thuslabeled in FIG. 1. Other keyboard embodiments may comprise differentphysical key shapes, key sizes, key locations or orientations, ordifferent key layouts such as DVORAK layouts or layouts designed for usewith special applications or non-English languages. In some embodiments,the keys 120 comprise keycaps that are rigid bodies, such as rigidrectangular bodies having greater width and breadth than depth (depthbeing in the Z direction as explained below). Also, other keyboardembodiments may comprise a single pressable key-based touchsurfaceconfigured in accordance with the techniques described herein, such thatthe other keys of these other keyboard embodiments are configured withother techniques.

Orientation terminology is introduced here in connection with FIG. 1,but is generally applicable to the other discussions herein and theother figures unless noted otherwise. This terminology introduction alsoincludes directions associated with an arbitrary Cartesian coordinatesystem. The arrows 110 indicate the positive directions of the Cartesiancoordinate system, but do not indicate an origin for the coordinatesystem. Definition of the origin will not be needed to appreciate thetechnology discussed herein.

The face of keyboard 100 including the exposed touchsurfaces configuredto be pressed by users is referred to as the “top” 102 of the keyboard100 herein. Using the Cartesian coordinate directions indicated by thearrows 110, the top 102 of the keyboard 100 is in the positive-Zdirection relative to the bottom 103 of the keyboard 100. The part ofthe keyboard 100 that is typically closer to the body of a user when thekeyboard 100 is in use atop a table top is referred to as the “front”104 of the keyboard 100. In a QWERTY layout, the front 104 of thekeyboard 100 is closer to the space bar and further from thealphanumeric keys. Using the Cartesian coordinate directions indicatedby the arrows 110, the front 104 of the keyboard 100 is in thepositive-X direction relative to the back 105 of the keyboard 100. In atypical use orientation where the top 102 of the keyboard 100 is facingupwards and the front 104 of the keyboard 100 is facing towards theuser, the “right side” 106 of the keyboard 100 is to the right of auser. Using the Cartesian coordinate directions indicated by the arrows110, the right side 106 of the keyboard 100 is in the positive-Ydirection relative to the “left side” 107 of the keyboard 100. With thetop 102, front 104, and right side 106 thus defined, the “bottom” 103,“back” 105, and “left side” 107 of the keyboard 100 are also defined.

Using this terminology, the press direction for the keyboard 100 is inthe negative-Z direction, or vertically downwards toward the bottom ofthe keyboard 100. The X and Y directions are orthogonal to each otherand to the press direction. Combinations of the X and Y directions candefine an infinite number of additional lateral directions orthogonal tothe press direction. Thus, example lateral directions include the Xdirection (positive and negative), the Y direction (positive andnegative), and combination lateral directions with components in boththe X and Y directions but not the Z direction. Motion components in anyof these lateral directions is sometimes referred herein as “planar,”since such lateral motion components can be considered to be in a planeorthogonal to the press direction.

Some or all of the keys of the keyboard 100 are configured to movebetween respective unpressed and pressed positions that are spaced inthe press direction and in a lateral direction orthogonal to the pressdirection. That is, the touchsurfaces of these keys exhibit motionhaving components in the negative Z-direction and in a lateraldirection. In the examples described herein, the lateral component isusually in the positive X-direction or in the negative X-direction forease of understanding. However, in various embodiments, and withreorientation of select key elements as appropriate, the lateralseparation between the unpressed and the pressed positions may be solelyin the positive or negative X-direction, solely in the positive ornegative Y-direction, or in a combination with components in both the Xand Y directions.

Thus, these keys of the keyboard 100 can be described as exhibiting“diagonal” motion from the unpressed to the pressed position. Thisdiagonal motion is a motion including both a “Z” (or vertical)translation component and a lateral (or planar) translation component.Since this planar translation occurs with the vertical travel of thetouchsurface, it may be called “planar translational responsiveness tovertical travel” of the touchsurface, or “vertical-lateral travel.”

Some embodiments of the keyboard 100 comprise keyboards with leveledkeys that remain, when pressed during normal use, substantially level inorientation through their respective vertical-lateral travels. That is,the keycaps of these leveled keys (and thus the touchsurfaces of thesekeys) exhibit little or no rotation along any axes in response topresses that occur during normal use. Thus, there is little or no roll,pitch, and yaw of the keycap and the associated touchsurfaces remainrelatively level and substantially in the same orientation during theirmotion from the unpressed position to the pressed position.

In various embodiments, the lateral motion associated with thevertical-lateral travel can improve the tactile feel of the key byincreasing the total key travel for a given amount of vertical travel inthe press direction. In various embodiments, the vertical-lateral travelalso enhances tactile feel by imparting to users the perception that thetouchsurface has travelled a larger vertical distance than actuallytravelled. For example, the lateral component of vertical-lateral travelmay apply tangential friction forces to the skin of a finger pad incontact with the touchsurface, and cause deformation of the skin andfinger pad that the user perceives as additional vertical travel. Thisthen creates a tactile illusion of greater vertical travel. In someembodiments, returning the key from the pressed to the unpressedposition on the return stroke also involves simulating greater verticaltravel using lateral motion.

To enable the keys 120 of the keyboard 100 with vertical-lateral travel,the keys 120 are parts of key assemblies each comprising mechanisms foreffecting planar translation, readying the key 120 by holding theassociated keycap in the unpressed position, and returning the key 120to the unpressed position. Some embodiments further comprise mechanismsfor leveling keycaps. Some embodiments achieve these functions with aseparate mechanism for each function, while some embodiments achieve twoor more of these functions using a same mechanism. For example, a“biasing” mechanism may provide the readying function, the returningfunction, or both the readying and returning functions. Mechanisms whichprovide both readying and returning functions are referred to herein as“ready/return” mechanisms. As another example, aleveling/planar-translation-effecting mechanisms may level and effectplanar translation. As further examples, other combinations of functionsmay be provided by a same mechanism.

The keyboard 100 may use any appropriate technology for detectingpresses of the keys of the keyboard 100. For example, the keyboard 100may employ a key switch matrix based on conventional resistive membraneswitch technology. The key switch matrix may be located under the keys120 and configured to generate a signal to indicate a key press when akey 120 is pressed. Alternatively, the example keyboard 100 may employother key press detection technology to detect any changes associatedwith the fine or gross change in position or motion of a key 120.Example key press detection technologies include various capacitive,resistive, inductive, magnetic, force or pressure, linear or angularstrain or displacement, temperature, aural, ultrasonic, optical, andother suitable techniques. With many of these technologies, one or morepreset or variable thresholds may be defined for identifying presses andreleases.

As a specific example, capacitive sensor electrodes may be disposedunder the touchsurfaces, and detect changes in capacitance resultingfrom changes in press states of touchsurfaces. The capacitive sensorelectrodes may utilize “self capacitance” (or “absolute capacitance”)sensing methods based on changes in the capacitive coupling between thesensor electrodes and the touchsurface. In some embodiments, thetouchsurface is conductive in part or in whole, or a conductive elementis attached to the touchsurface, and held at a constant voltage such assystem ground. A change in location of the touchsurface alters theelectric field near the sensor electrodes below the touchsurface, thuschanging the measured capacitive coupling. In one implementation, anabsolute capacitance sensing method operates with a capacitive sensorelectrode underlying a component having the touchsurface, modulates thatsensor electrodes with respect to a reference voltage (e.g., systemground), and detects the capacitive coupling between that sensorelectrode and the component having the touchsurface for gauging thepress state of the touchsurface.

Some capacitive implementations utilize “mutual capacitance” (or“transcapacitance”) sensing methods based on changes in the capacitivecoupling between sensor electrodes. In various embodiments, theproximity of a touchsurface near the sensor electrodes alters theelectric field between the sensor electrodes, thus changing the measuredcapacitive coupling. The touchsurface may be a conductive ornon-conductive, electrically driven or floating, as long as its motioncauses measurable change in the capacitive coupling between sensorelectrodes. In some implementations, a transcapacitive sensing methodoperates by detecting the capacitive coupling between one or moretransmitter sensor electrodes (also “transmitters”) and one or morereceiver sensor electrodes (also “receivers”). Transmitter sensorelectrodes may be modulated relative to a reference voltage (e.g.,system ground) to transmit transmitter signals. Receiver sensorelectrodes may be held substantially constant relative to the referencevoltage to facilitate receipt of resulting signals. A resulting signalmay comprise effect(s) corresponding to one or more transmitter signals,and/or to one or more sources of environmental interference (e.g., otherelectromagnetic signals). Sensor electrodes may be dedicatedtransmitters or receivers, or may be configured to both transmit andreceive.

In one implementation, a trans-capacitance sensing method operates withtwo capacitive sensor electrodes underlying a touchsurface, onetransmitter and one receiver. The resulting signal received by thereceiver is affected by the transmitter signal and the location of thetouchsurface.

In some embodiments, the sensor system used to detect touchsurfacepresses may also detect pre-presses. For example, a capacitive sensorsystem may also be able to detect a user lightly touching atouchsurface, and distinguish that from the press of the touchsurface.Such a system can support multi-stage touchsurface input, which canrespond differently to light touch and press.

Some embodiments are configured to gauge the amount of force beingapplied on the touchsurface from the effect that the force has on thesensor signals. That is, the amount of depression of the touchsurface iscorrelated with one or more particular sensor readings, such that theamount of press force can be determined from the sensor reading(s).

In some embodiments, substrates used for sensing are also used toprovide backlighting associated with the touchsurfaces. As a specificexample, in some embodiments utilizing capacitive sensors underlying thetouchsurface, the capacitive sensor electrodes are disposed on atransparent or translucent circuit substrate such as polyethyleneterephthalate (PET), another polymer, or glass. Some of thoseembodiments use the circuit substrate as part of a light guide systemfor backlighting symbols viewable through the touchsurfaces.

FIG. 1 also shows a section line A-A′ relative to the key 122 of thekeyboard 100, which will be discussed below.

The keyboard 100 may be integrated into or coupled to computer such as alaptop computer comprising one or more processing systems. Theprocessing system(s) each comprise one or more ICs (integrated circuits)having appropriate processor-executable instructions for responding tokey presses. These instructions direct the appropriate IC(s) to operatekeyboard sensors to determine if a key has been pressed (or the extentof the press), and provide an indication of press status to a main CPUof the laptop or a response to the press status to a user of the laptop.

While the orientation terminology, vertical-lateral travel, sensingtechnology, and implementation options discussed here focuses on thekeyboard 100, these discussions are readily analogized to othertouchsurfaces and devices described herein.

Various embodiments in accordance with the techniques described herein,including embodiments without metal snap domes or rubber domes, provideforce response curves similar to the curve 210 of FIG. 2. Many tactilekeyboard keys utilize snap ratios no less than 0.4 and no more than 0.6.Other tactile keyboard keys may use snap ratios outside of these ranges,such as no less than 0.3 and no more than 0.5, and no less than 0.5 andno more than 0.7.

Other embodiments provide other response curves having other shapes,including those with force and key travel relationships that are linearor nonlinear. Example nonlinear relationships include those which arepiecewise linear, which contain linear and nonlinear sections, or whichhave constantly varying slopes. The force response curves may also benon-monotonic, monotonic, or strictly monotonic.

For example, the keys 120 made in accordance with the techniquesdescribed herein may be configured to provide the response shown bycurve 210, or any appropriate response curve. The reaction force appliedto a user may increase linearly or nonlinearly relative to an amount oftotal key travel, an amount of key travel the press direction, or anamount of key travel in a lateral direction. As a specific example, theforce applied may increase with a constant slope relative to the amountof key travel for up to a first amount of force or key movement relativeto its unpressed position, and then plateau (with constant force) ordecrease for up to a second amount of force or key movement.

FIGS. 3A-3B are simplified cross-sectional views of a first exampletouchsurface assembly. The key assembly 300 may be used to implementvarious keys, including the key 122 of the keyboard 100. In theembodiment where FIGS. 3A-3B depict the key 122, these figuresillustrate A-A′ sectional views of the key 122. FIG. 3A shows theexample key assembly 300 in an unpressed position and FIG. 3B shows thesame key assembly 300 in a pressed position. The key assembly 300 mayalso be used in other devices utilizing keys, including keyboards otherthan the keyboard 100 and any other appropriate key-using device.Further, assemblies analogous to the key assembly 300 may be used toenable non-key touchsurface assemblies such as buttons, opaquetouchpads, touchscreens, or any of the touchsurface assemblies describedherein.

The key assembly 300 includes a keycap 310 that is visible to users andconfigured to be pressed by users, a ready/return mechanism 320, and abase 340. The unpressed and pressed positions of the keycap 310 arespaced in a press direction and in a first lateral direction orthogonalto the press direction. The press direction is analogous to the keymotion found in conventional keyboards lacking lateral key motion, is inthe negative-Z direction, and is the primary direction of press and keymotion. In many keyboards the press direction is orthogonal to thetouchsurface of the keycap or the base of the key, such that users wouldconsider the press direction to be downwards toward the base.

The components of the key assembly 300 may be made from any appropriatematerial, including plastics such as polycarbonate (PC), acrylonitrilebutadiene styrene (ABS), nylon, and acetal, metals such as steel andaluminum, elastomers such as rubber, and various other materials. Invarious embodiments, the keycap 310 is configured to be substantiallyrigid, such that the touchsurface of the keycap 310 appears to unaidedhuman senses to move with rigid body motion between its unpressed andpressed positions during normal operation.

The ready/return mechanism 320 is a type of “biasing mechanism” thatprovides both readying and returning functions. The ready/returnmechanism 320 physically biases the keycap 310 during at least part ofthe key press operation. It should be noted that a mechanism which onlyprovides readying or returning function may also be termed a “biasingmechanism,” if it biases the keycap 310 during at least part of the keypress operation. The ready/return mechanism 320 is configured to holdthe keycap 310 in its unpressed position so that the keycap 310 is readyto be pressed by a user. In addition, the ready/return mechanism 320 isalso configured to return the keycap 310 partially or entirely to theunpressed position in response to a release of the press force to keycap310. The release of the press force may be a removal of the press force,or a sufficient reduction of press force such that the key assembly isable to return the keycap 310 to the unpressed position as a matter ofnormal operation. In the example embodiment of FIG. 3, the key assembly300 utilizes magnetically coupled components 322, 324 to form theready/return mechanism 320. Magnetically coupled components 322, 324 mayboth comprise magnets, or one may comprise a magnet while the othercomprise a magnetically coupled material such as a ferrous material.Although magnetically coupled components 322, 324 are each shown as asingle rectangular shape, either or both magnetically coupled components322, 324 may comprise non-rectangular cross-section(s) or comprise aplurality of magnetically coupled subcomponents having the same ordifferent cross sections. For example, magnetically coupled component322 or 324 may comprise a magnetic, box-shaped subcomponent disposedagainst a central portion of a ferrous, U-shaped subcomponent.

In some implementations, the magnetically coupled component 322 isphysically attached to a bezel or base proximate to the keycap 310. Themagnetically coupled component 324 is physically attached to the keycapand magnetically interacts with the magnetically coupled component 322.The physical attachment of the magnetically coupled components 322, 324may be direct or indirect (indirectly being through one or moreintermediate components), and may be accomplished by press fits,adhesives, or any other technique or combination of techniques. Theamount of press force needed on the keycap to overcome the magneticcoupling (e.g., overpower the magnetic attraction or repulsion) can becustomized based upon the size, type, shape, and positions of themagnetically coupling components 322, 324 involved.

The key assembly 300 comprises a planar-translation-effecting (PTE)mechanism 330 configured to impart planar translation to the keycap 310when it moves between the unpressed and pressed positions, such that anonzero component of lateral motion occurs. The PTE mechanism 330 isformed from parts of the keycap 310 and the base 340, and comprises fourramps (two ramps 331, 332 are visible in FIGS. 3A-B) disposed on thebase 340. These four ramps are located such that they are proximate tothe corners of the keycap 310 when the key assembly 300 is assembled. Inthe embodiment shown in FIGS. 3A-B, these four ramps (including ramps331, 332) are simple, sloped planar ramps located at an angle to thebase 340. These four ramps (including ramps 331, 332) are configured tophysically contact corresponding ramp contacting features (two rampcontacting features 311, 312 are visible in FIGS. 3A-B) disposed on theunderside of the keycap 310. The ramp contacting features of the keycap310 may be any appropriate shape, including ramps matched to those ofthe ramps on the base 340.

In response to a press force applied to the touchsurface of the keycap310 downwards along the press direction, the ramps on the base 340(including ramps 331, 332) provide reaction forces. These reactionforces are normal to the ramps and include lateral components that causethe keycap 310 to exhibit lateral motion. The ramps and some retentionor alignment features that mate with other features in the bezel orother appropriate component (not shown) help retain and level the keycap310. That is, they keep the keycap 310 from separating from the rampsand in substantially the same orientation when travelling from theunpressed to the pressed position.

As shown by FIGS. 3A-B, the keycap 310 moves in the press direction(negative Z-direction) in response to a sufficiently large press forceapplied to the top of the keycap 310. As a result, the keycap 310 movesin a lateral direction (in the positive X-direction) and in the pressdirection (in the negative Z-direction) due to the reaction forcesassociated with the ramps. The ramp contacting features (e.g., 311, 312)of the keycap 310 ride on the ramps of the base 340 (e.g., 331, 332) asthe keycap 310 moves from the unpressed to the pressed position. Thismotion of the keycap 310 moves the magnetically coupled components 322,324 relative to each other, and changes their magnetic interactions.

FIG. 3B shows the keycap 310 in the pressed position. For the keyassembly 300, the keycap 310 has moved to the pressed position when itdirectly or indirectly contacts the base 340 or has moved far enough tobe sensed as a key press. FIG. 3A-B do not illustrate the sensor(s) usedto detect the press state of the keycap 310, and such sensor(s) may bebased on any appropriate technology, as discussed above.

When the press force is released, the ready/return mechanism 320 returnsthe keycap 310 to its unpressed position. The attractive forces betweenthe magnetically coupled components 322, 324 pull the keycap 310 back upthe ramps (including the ramps 331, 322), toward the unpressed position.

Many embodiments using magnetic forces utilize permanent magnets.Example permanent magnets include, in order of strongest magneticstrength to the weakest: neodymium iron boron, samarium cobalt, alnico,and ceramic. Neodymium-based magnets are rare earth magnets, and arevery strong magnets made from alloys of rare earth elements. Alternativeimplementations include other rare earth magnets, non-rare earthpermanent magnets, and electromagnets.

Although the key assembly 300 utilizes magnetically coupled componentsto form its ready/return mechanism 320, various other techniques can beused instead or in addition to such magnetic techniques in otherembodiments. In addition, separate mechanisms may be used to accomplishthe readying and returning functions separately. For example, one ormore mechanisms may retain the keycap in its ready position and one ormore other mechanisms may return the keycap to its ready position.Examples of other readying, returning, or ready/return mechanismsinclude buckling elastomeric structures, snapping metallic domes,deflecting plastic or metal springs, stretching elastic bands, bendingcantilever beams, and the like. In addition, in some embodiments, theready/return mechanism push (instead of pull) the keycap 310 to resistkeycap motion to the pressed position or to return it to the unpressedposition. Such embodiments may use magnetic repulsion or any otherappropriate technique imparting push forces.

Many variations of or additions to the components of the key assembly300 are possible. For example, other embodiments may include fewer ormore components. As a specific example, another key assembly mayincorporate any number of additional aesthetic or functional components.Some embodiments include bezels that provide functions such as hidingsome of the key assembly from view, protecting the other components ofthe key assembly, helping to retain or guide the touchsurface of the keyassembly, or some other function.

As another example, other embodiments may comprise different keycaps,readying mechanisms, returning mechanisms, PTE mechanisms, levelingmechanisms, or bases. As a specific example, the keycap 310, the base340, or another component that is not shown may comprise protrusions,depressions, or other features that help guide or retain the keycap 310.As another specific example, some embodiments use non-ramp techniques inplace or (or in addition to) ramps to effect planar translation.Examples other PTE mechanisms include various linkage systems, cams,pegs and slots, bearing surfaces, and other motion alignment features.

As yet another example, although the PTE mechanism 330 is shown in FIGS.3A-B as having ramps disposed on the base 340 and ramp contactingfeatures disposed on the keycap 310, other embodiments may have one ormore ramps disposed on the keycap 310 and ramp contacting featuresdisposed on the base 340. Also, the PTE mechanism 330 is shown in FIGS.3A-B as having ramps 331, 332 with simple, sloped plane ramp profiles.However, in various embodiments, the PTE mechanism 330 may utilize otherprofiles, including those with linear, piecewise linear, or nonlinearsections, those having simple or complex curves or surfaces, or thoseincluding various convex and concave features. Similarly, the rampcontacting features on the keycap 310 may be simple or complex, and maycomprise linear, piecewise linear, or nonlinear sections. As somespecific examples, the ramp contacting features may comprise simpleramps, parts of spheres, sections of cylinders, and the like. Further,the ramp contacting features on the keycap 310 may make point, line, orsurface contact the ramps on the base 340 (including ramps 331, 332).“Ramp profile” is used herein to indicate the contour of the surfaces ofany ramps used for the PTE mechanisms. In some embodiments, a singlekeyboard may employ a plurality of different ramp profiles in order toprovide different tactile responses for different keys.

As a further example, embodiments which level their touchsurfaces mayuse various leveling techniques which use none, part, or all of theassociate PTE mechanism.

FIG. 4 shows an exploded view of an example keyboard construction 400 inaccordance with the techniques described herein. A construction like thekeyboard construction 400 may be used to implement any number ofdifferent keyboards, including keyboard 100. Proceeding from the top tothe bottom of the keyboard, the bezel 420 comprises a plurality ofapertures through which keycaps 410 of various sizes are accessible inthe final assembly. Magnetically coupled components 422, 424 areattached to the keycaps 410 or the base 440, respectively. The base 440comprises a plurality of PTE mechanisms (illustrated as simplerectangles on the base 440) configured to guide the motion of thekeycaps 410. Underneath the base 440 is a key sensor 450, whichcomprises one or more layers of circuitry disposed on one or moresubstrates.

Various details have been simplified for ease of understanding. Forexample, adhesives that may be used to bond components together are notshown. Also, various embodiments may have more or fewer components thanshown in keyboard construction 400, or the components may be in adifferent order. For example, the base and the key sensor 450 may becombined into one component, or swapped in the stack-up order.

FIGS. 5A-B are cross-sectional side views of a key assembly 500 inaccordance with a key retracting embodiment. FIG. 5A illustrated the keyassembly 500 in an unpressed (or ready) position and FIG. 5B shows thekey assembly in the retracted position. As will be discussed below, aplanar translation effecting mechanism is used in some embodiments toform a portion of a key retraction mechanism for the key assembly 500.

The key assembly 500 comprises a keycap 502 having a touch surface 504configured to receive a press force from a user and a chassis 506. Abezel or cover 508 (commonly referred to as the “C” cover) is configuredabove the chassis and includes a key holder feature 510 that forms aportion of a key retraction mechanism that retracts the keycap 502toward a retracted position as will be discussed below. The key assembly500 also includes a planar translation effecting (PTE) mechanism thatcomprises ramps 512 and 514 that guide ramp contacting features 516 and518 of the keycap 502 from the unpressed position toward the pressedposition. In normal (typing) operation, a press force 520 is applied bya user to the touch surface 504 and the ramp contacting features 516 and518 move along the ramps 512 and 514 in the press direction (Zdirection) and also in a second direction (X direction) orthogonal tothe press direction. The PTE mechanism also includes inverted or reverseramps 522 in the chassis 506 and reverse ramp contacting features 524 inthe keycap 502. The reverse ramps 522 operate to drive the keycap 502toward the ramp 512 in the event the touch surface 504 is pressedoff-center. As the keycap 502 nears the pressed position, a sensor 522can detect the key press and provide a sensing signal to any processingsystem employed in any particular implementation. Upon removal of thepress force 520, the magnetic attraction of the ready-return mechanism(320 of FIG. 3) draws the keycap 502 back toward the unpressed (ready)position.

The sensor 526 may use any appropriate technology, including any of theones described herein. In some embodiments, the sensor 526 detectschanges in capacitance, the keycap 502 comprises primarily dielectricmaterial, and the change in the position of the dielectric material ofthe keycap 502 causes the primary changes in capacitance detected by thesensor 526. In some embodiments, the sensor 526 detect changes incapacitance, conductive material is disposed in or on the keycap 502,and the change in position of the conductive material of the keycap 502causes the primary changes in capacitance detected by the sensor 526. Insome embodiments, the sensor 526 is configured to actively detectunpressed and pressed positions of the keycap 502. In some embodiments,the sensor 526 is configured to actively detect only the pressed stateof the keycap 502, and it is assumed that no detection of the pressedstate means the keycap 502 is unpressed, or vice versa. A processingsystem (not shown) communicatively coupled to the sensor 526 operatesthe sensor 526 to produce signals indicative of the pressed state of thekey assembly, and determines a press state of the keycap 502 based onthese signals. As the keycap 502 moves toward the retracted position,the sensor 516 may be deactivated or the sensor signals ignored and notprocessed so as not to provide the processing system with numerouserroneous key press indications.

According to exemplary embodiments, the PTE mechanism forms a portion ofthe key retraction mechanism along with the key holding feature 510 ofthe bezel 508. A plurality of retractable key assemblies 500 may beincorporated in keyboards or keypads to provide different advantages. Insome embodiments, keyboards or keypads with retractable key assembliesprovide thinner profiles when the keycaps 502 are retained in theretracted position. In some laptop or laptop-tablet hybrid embodiments,the thinner profile of a retracted keyboard allows the display to becloser to the base of the keyboard when closed, reducing the overallthickness of the computer system (compared keyboards with keys in theirunpressed positions). In some embodiments, the key-bearing surfaces ofkeyboards or keypads with retracted keys can be used as support surfacesfor objects or provide flat touch input surfaces. As a specific example,a tablet computer may be configured to rest on the key-bearing surfaceof its tablet cover.

In some embodiments, the keycap 502 may be retracted by movement of thechassis 506 relative to the bezel 508 as indicated by arrow 528. In thisembodiment, the key holding feature 510 of the bezel 508 prevents thekeycap 502 from moving with the chassis 506. As the chassis moves (inthe negative X direction in this example) the reverse ramp 522 andreverse ramp contacting feature 524 cause the keycap 502 to be guided bythe PTE mechanism toward a retracted position. In some embodiments, theretracted position may be substantially the same key position as thepressed position. In some embodiments, the keycap 502 may be retractedby movement of the bezel 508 relative to the chassis 506 as indicated byarrow 530. In this embodiment, the key holding feature 510 of the bezel508 moves (pushes) the keycap as the chassis moves (in the positive Xdirection in this example) into the reverse ramp 522 and reverse rampcontacting feature 524, which cause the keycap 502 to be guided by thePTE mechanism toward a retracted position. In some embodiments, thechassis 506 and the bezel 508 remain stationary and the key holdingfeature 510 is configured to move relative to chassis 506 and the bezel508. The movement of the key holding feature 510 in this embodiment alsomoves (pushes) the keycap (in the positive X direction) to be guided bythe PTE mechanism toward the retracted position.

In those embodiments employing a magnetic ready-return mechanism, theforce required to move the chassis 506 and the bezel 508 relative toeach other may be quite high. For example, if a press force ofapproximately eighty grams was require to overcome the magneticattraction of the ready-return mechanism, then the force required tomove the chassis 506 and the bezel 508 relative to each other would beapproximately eighty grams multiplied by the number of key assemblies inthe particular keypad or keyboard. Additionally, any friction in thecollective ramps/ramp contacting features of the keyboard system couldincrease the required key retraction force. Accordingly, someembodiments employ a bias mechanism 532 that operates to apply a biasforce 534 to the chassis. In some embodiments, the bias force 534 isselected to be greater than the collective magnetic forces of theready-return mechanisms so that the keycaps are normally retracted. Insome embodiments, the bias force 534 is selected to be less than thecollective magnetic forces of the ready-return mechanisms so that theykeycaps are normally not retracted, however, the bias force 534 reducesthe additional force required to move the keycaps toward the retractedposition.

FIGS. 6 A-C are side view illustrations of an exemplary embodiment ofthe key retraction mechanism for a laptop computer 600 implementation.As shown in FIG. 6A, the keycaps 602 are in the unpressed position wherethe touch surface of the keycaps are above the bezel 604 as indicated at606. As the display 608 moves toward the bezel 604 the key retractionmechanism engages (FIG. 6B) and moves the keycaps toward retractedposition as indicated at 610. When the display 608 closes to meet thebezel 604 (FIG. 6C), the keycaps 602 have retracted to be substantiallyflush with the bezel 602. The reverse motion of the display 608 willcause the keycaps 602 to rise to the unpressed position.

FIGS. 7 A-D are illustrations of exemplary key retraction mechanismsthat may be employed in any particular implementation. In FIG. 7 A, acomputer 700 includes keycaps 702, a bezel 704 and a cover or display706. As the cover 706 approaches the bezel 704, a cam 708 engages an arm710 of the chassis, which moves the chasses relative to the bezel. Thekey holding features of the bezel operate to retract the keycaps asdiscussed above in connection with FIG. 5.

FIG. 7 B illustrates a convertible computer embodiment in which thecover 706 may be folded over the bezel 704 so that the convertiblecomputer may be used as a tablet computer. A hinge 712 includes aportion 714 that engages an arm 716 of the chassis as the cover 706approaches the bezel 704. This operation moves the chassis relative tothe bezel and the key holding features of the bezel operate to retractthe keycaps.

FIG. 7 C illustrates another embodiment that utilizes the operation of arack 718 and pinion 720 to move the chassis relative to the bezel. Inyet another embodiment, FIG. 7D employs a latch 722 having a beveledsurface 724. As the cover 706 approaches the bezel 704, the later passesthrough an aperture 726 where the beveled surface 724 engages acorresponding bevel 728 of the chassis 730. The interaction of thebeveled surfaces 724 and 728 move the chassis 730 relative to the bezel704 to retract the keycaps 702.

As will be appreciated, any number of mechanisms may be employed to movethe chassis and bezel relative to one another. Examples range fromsimply coupling a strap or ribbon between the chassis and the cover topull-push the chassis as the cover opens and closes. More complexexamples include motorized systems to move the chassis relative to thebezel. In such a motorized retraction mechanism a control system mayretract or protrude the keycaps as appropriate, such as in response tosystem status, user hand position and the like. For example, in anembodiment with sensors that detect the proximity of the user's palm,fingers, or other hand portions to determine when the user isapproaching a “ready to type” position, the motorized retractionmechanism moves the keys to their ready position in response to adetermination that the user is preparing to type.

FIGS. 8A-B are simplified cross-sectional side views of a key assembly800 in accordance with an embodiment. FIG. 8A illustrated the keyassembly 800 in an unpressed (or ready) position and FIG. 8B shows thekey assembly in the pressed position. As can be seen, in the pressedposition, the key holding feature 814 has held the keycap 802 of the keyassembly 800 while the base 804 has moved in a negative X direction 816.The keycap 802 thus moves in the press direction (Z direction) via afour-bar planar translation effecting mechanism 808 coupled between thechassis 804 and the keycap 802. A magnetic ready-return mechanismincludes a magnet 812 and a magnetic ferrous portion of the chassis 810.The four-bar planar translation effecting mechanism 808 provides asimplified PTE mechanism that may be less expensive or more readilyimplemented as compared to the ramp and ramp contacting features of FIG.5.

FIGS. 9A-B are simplified cross-sectional side views of a key assembly900 in accordance with an embodiment. FIG. 9A illustrated the keyassembly 900 in an unpressed (or ready) position and FIG. 9B shows thekey assembly in the pressed position. In this embodiment, the base 904is moved in the positive X direction 912 causing the a portion 910 ofthe ready-return mechanism to push the keycap along the dual translationpath in the press direction (Z direction) and the positive X directionvia a four-bar planar translation effecting mechanism 908 coupledbetween the chassis 904 and the keycap 902. Again, this four-bar planartranslation effecting mechanism 908 provides a simplified PTE mechanismthat may be less expensive or more readily implemented as compared tothe ramp and ramp contacting features of FIG. 5.

Thus, the techniques described herein can be used to implement anynumber of devices utilizing different touchsurface assemblies, includinga variety of keyboards each comprising one or more key assemblies inaccordance with the techniques described herein. Some components may beshared when multiple touchsurfaces are placed in the same device. Forexample, the base may be shared by two or more touchsurfaces. As anotherexample, the keyswitch sensor may be shared through sharing sensorsubstrates, sensor electrodes, or the like.

The implementations described herein are meant as examples, and manyvariations are possible. As one example, any appropriate featuredescribed with one implementation may be incorporated with another. As afirst specific example, any of the implementations described herein mayor may not utilize a finishing tactile, aesthetic, or protective layer.As a second specific example, ferrous material may be used to replacemagnets in various magnetically coupled component arrangements.

In addition, the structure providing any function may comprise anynumber of appropriate components. For example, a same component mayprovide leveling, planar translation effecting, readying, and returningfunctions for a key press. As another example, different components maybe provide these functions, such that a first component levels, a secondcomponent effects planar translation, a third component readies, and afourth component returns. As yet another example, two or more componentsmay provide a same function. For example, in some embodiments, magnetsand springs together provide the return function, or the ready andreturn functions. Thus, the techniques described in the variousimplementations herein may be used in conjunction with each other, evenwhere the function may seem redundant. For example, some embodiments usesprings to back-up or augment magnetically-based ready/returnmechanisms.

What is claimed is:
 1. A keyboard, comprising: a bezel having aplurality of key openings and a plurality of key holding featuresconfigured adjacent to the plurality of key openings on a bottom side ofthe bezel; a plurality of keycaps each positioned within a respectiveone of the plurality of key openings and each having a touch surface forreceiving a press force that moves the keycap from an unpressed positiontoward a pressed position, the unpressed position and pressed positionseparated in a press direction and a second direction orthogonal to thepress direction; a chassis having a plurality of planar-translationeffecting mechanisms each supporting a respective one of the pluralityof keycaps to guide the respective keycap in the press direction and thesecond direction as the keycap moves from the unpressed position towardthe pressed position; and a key retraction mechanism configured to movethe chassis relative to the bezel; wherein the key holding features ofthe bezel are configured to limit movement of the keycaps in the seconddirection during movement of the chassis relative to the bezel, whilethe planar-translation effecting mechanism move the plurality of keycapstoward a retracted position.
 2. The keyboard of claim 1, wherein: eachof the plurality of keycaps includes a first magnetic component; thechassis includes a second magnetic component for each respective keycapof the plurality of keycaps; and the first and second magneticcomponents form a ready-return mechanism that biases the respectivekeycap toward the unpressed position.
 3. The keyboard of claim 2,wherein one of the first and second magnetic components comprises anon-magnetized ferrous material.
 4. The keyboard of claim 1, furthercomprising a biasing mechanism coupled to the chassis and configured tobias the plurality of keycaps toward the retracted position.
 5. Thekeyboard of claim 4, wherein a magnitude of a biasing force provided bythe biasing mechanism is slightly larger than a magnetic force providedby the ready-return mechanisms.
 5. The keyboard of claim 1, wherein eachof the planar-translation effecting mechanisms comprise a four barlinkage configured between the chassis and a respective keycap.
 6. Thekeyboard of claim 5, wherein the four bar linkage is configured with thechassis connection as a grounded link and the keycap connection as thefloating link.
 7. The keyboard of claim 1, wherein each of theplanar-translation effecting mechanisms comprise ramp features on thechassis for each respective keycap and the plurality of keycaps includeramp contacting features the move along the ramp features as therespective keycap moves from the unpressed position toward the pressedposition.
 8. The keyboard of claim 7, wherein the planar-translationeffecting mechanism further comprises inverted ramp features on thechassis for each respective keycap and the plurality of keycaps includeinverted ramp contacting features, the key holding features of the bezelhold the plurality of keycaps during movement to a retracted position.9. The keyboard of claim 8, wherein movement of the keycaps toward theretracted position comprises movement substantially in the pressdirection relative to the key holding features.
 10. The keyboard ofclaim 1, wherein each of the plurality of keycaps are substantiallyflush with a top surface of the bezel when the plurality of keycaps arein the retracted position.
 11. The keyboard of claim 1, furthercomprising a lid coupled to the key retraction mechanism, whereinmovement of the lid toward the bezel causes the key retraction mechanismto move the chassis relative the bezel thereby moving the plurality ofkeys to the retracted position.
 12. The keyboard of claim 12, whereinthe lid comprises a display.
 13. The keyboard of claim 1, furthercomprising a plurality of capacitive sensors each for sensing when therespective keycap is in the pressed position.
 14. The keyboard of claim12, wherein signals from the plurality of capacitive sensors are notprocessed when the key retraction mechanism moves the chassis relativeto the bezel.
 15. A keyboard, comprising: a bezel having a plurality ofkey openings and a plurality of key holding features configured adjacentto the plurality of key openings on a bottom side of the bezel; aplurality of keycaps each positioned within a respective one of theplurality of key openings and each having a touch surface for receivinga press force that moves the keycap from an unpressed position toward apressed position, the unpressed position and pressed position separatedin a press direction and a second direction orthogonal to the pressdirection; a chassis having a plurality of ramp features eachinteracting with ramp contacting features of a respective one of theplurality of keycaps to guide the respective keycap in the pressdirection and the second direction as the keycap moves from theunpressed position toward the pressed position, the chassis alsoincluding a plurality of inverted ramp features each interacting withinverted ramp contacting features of a respective one of the pluralityof keycaps; and a key retraction mechanism configured to cause movementbetween the chassis and the bezel; wherein the key holding features ofthe bezel are configured to limit movement of the keycaps in the seconddirection in response to movement of the chassis relative to the bezelwhile the inverted ramps and inverted ramp contacting features move theplurality of keycaps toward a retracted position.
 16. The keyboard ofclaim 15, wherein: each of the plurality of keycaps includes a firstmagnetic component; the chassis includes a second magnetic component foreach respective keycap of the plurality of keycaps; and the first andsecond magnetic components form a ready-return mechanism that biases therespective keycap toward the unpressed position.
 17. The keyboard ofclaim 16, wherein one of the first and second magnetic componentscomprises a non-magnetized ferrous material.
 18. The keyboard of claim16, further comprising a biasing mechanism coupled to the chassis andconfigured to bias the plurality of keycaps toward the retractedposition.
 19. The keyboard of claim 18, wherein a magnitude of a biasingforce provided by the biasing mechanism is slightly larger than amagnetic force provided by the ready-return mechanisms.
 19. The keyboardof claim 15, further comprising a display coupled to the key retractionmechanism, wherein movement of the display toward the bezel causes thekey retraction mechanism to effect the movement between the chassis andthe bezel thereby moving the plurality of keys to the retractedposition.
 20. The keyboard of claim 15, wherein the plurality of keycapsare substantially flush with a top surface of the bezel when theplurality of keycaps are in the retracted position.
 21. The keyboard ofclaim 15, further comprising a plurality of capacitive sensors each forsensing when the respective keycap is in the pressed position.
 22. Amethod of effecting motion of a plurality of keycaps positioned in abezel of a keyboard, wherein each of the plurality of keycaps aresupported in an unpressed position by a planar-translation effectingmechanism of a chassis, each of the plurality of keycaps configured tomove between the unpressed position and a pressed position, wherein theunpressed and pressed positions are separated in a press direction andin a second direction orthogonal to the press direction, the methodcomprising: in response to movement between the chassis and the bezel,the planar-translation effecting mechanism moves each of the pluralityof keycaps toward the press direction to a retracted position.